In an earlier study researchers discovered a cup of coffee not only provides a boost of caffeine energy, but also it was observed it may prevent the onset of Alzheimer's disease. Now they have finally understood why.

Researchers knew caffeine was suppressing the rise of amyloid plaques in the brain, but the reason remained unknown. However, researchers from the University of Illinois now believe caffeine has a unique ability to block inflammation in the brain.

Gregory Freund professor at the University of Illinois conducted an experiment on two groups of mice. As a way to facilitate cognitive impairment, Freund interrupted the breathing and blood flow of the mice, through a process called hypoxia. Next he allotted the mice time to recover. Following their recovery, one group was administered caffeine, whereas the other group was not. 

The study revealed caffeine may minimize the impact of the chain reaction that occurs during cognitive impairment.

During the hypoxia process adenosine was released onto the brain cells, which is damaging to the brain. Adenosine molecules are what make up the fuel that powers an individual's brain. Freund observed once the so called "brain fuel" has leaked all over the brain cells, it was very similar to volatile gasoline leaking out of a tank endangering its setting.

Once this brain fuel has leaked, it activates other things such as the caspase-1 enzyme, which then sets off the production of beta cytokine IL-1. Beta cytokine IL-1 is an important factor in inflammation.

However, with caffeine adenosine molecules are blocked. Blocking the adenosine molecules prevents inflammation in the brain.

Alzheimer's disease is the most common form of dementia among older adults. According to the World Health Organization, nearly 18 million people worldwide suffer from Alzheimer's disease.

Researchers hope with caffeine's ability to block inflammation that could lead to new drugs to prevent or reverse cognitive impairment.

This study was published in the Journal of Neuroscience.